Properties Of Composites Research Articles

Achieving excellent physico-mechanical properties of Cu matrix composites by incorporating a low content of a three-dimensional graphene network

In-depth investigation of the distribution form of the reinforcement and associated mechanisms has great significance for fabricating highly strengthened and conductive Cu matrix composites. The three-dimensional graphene (3DG) network can withstand more strain due to its large specific surface area, and provides interlinked high-speed conductive paths within the composites. In this study, we propose a feasible method to fabricate 3DG-reinforced Cu matrix composites; here, the Cu foam serves as the initial substrate during the chemical vapour deposition (CVD) process and as the matrix of the composites. Through constructing an ideal 3DG network, the graphene content is approximately 0.28 vol%, and a remarkable 230 % improvement in the ultimate tensile strength (418 MPa) with a high electrical conductivity (97.02 %IACS) is obtained in the composite. The continuous high-quality 3DG network is conducive for achieving excellent physico-mechanical properties of the composites, and the enhanced efficiency is superior. A new concept of fabricating Cu matrix composites was proposed for future research.

Microstructures and mechanical properties of TiAl matrix composites with multi-precipitates quasi-continuous network reinforced structures

A novel quasi-continuous network reinforced structure that consists of borides and carbides in B4C/TiAl matrix composites was innovatively designed for the strengthening at high temperatures. Simultaneously, impacts of such reinforced structures on microstructures and mechanical properties of the composites have been unveiled. TiAl matrix units in B4C/TiAl composites are duplex microstructures which are composed of (α2+γ) colonies and γ grains. The ascent of B4C contents triggers off the formation of network reinforced structures in the layers of TiAl matrix units. With B4C contents increasing to 0.1wt.%, elasticity modulus and ultimate compressive strengths of B4C/TiAl composites are upgraded from 10.944GPa and 723.10MPa to 16.052GPa and 774.611MPa. As B4C contents reach at 5.0wt.%, elasticity modulus and ultimate compressive strengths further soar to 17.244GPa and 799.19MPa. Borides and carbides within the quasi-continuous network reinforced structures are unfolded as stripe and needle shaped TiB with B27 structure and Ti2AlC particles with MAX structure. Parts of Ti2AlC particles take TiB as cores to nucleate and grow. Moreover, TiC phases usually act as the cores for the nucleation of Ti2AlC particles. The orientation relationships of such reinforcements represent as [011]TiC//[010]TiB, (1-11)[011]TiC//(0006) [-2110]Ti2AlC, [100]TiB//[0001]Ti2AlC, [010]TiB//[-2110]Ti2AlC and [001]TiB//[01-10]Ti2AlC. The fractures of TiB are usually along or perpendicular to [010]TiB direction. Meanwhile, the fracture surfaces of TiB are always parallel to (100)TiB or (010)TiB planes. Additionally, dislocations slip through Ti2AlC particles and lead to separation and sliding of staking planes (0001)Ti2AlC within Ti2AlC lattices. TiB and Ti2AlC with alternative distribution can stabilize the network reinforced structures and upgrade properties of B4C/TiAl composites.

Mechanisms of microstructural evolution in high-volume TiC reinforced steel composites: Insights into particle coarsening, morphology, and thermochemical reactions

Titanium carbides reinforced steel matrix (TiC-steel) composites exhibit a range of excellent properties, including increased strength-to-weight ratio, high-temperature strength, and outstanding wear resistance. Prior research has demonstrated that the mechanical properties of TiC-steel composites are significantly affected by particle coarsening and the associated core-rim structure. Nevertheless, the fundamental mechanisms of thermochemical reactions that govern the formation of the final microstructure in these composites, including the core-rim structure, remain incompletely explored. This study elucidates the microstructure evolution mechanism of high-volume TiC-steel composites, particularly particle coarsening, through thermodynamic calculations and chemical analysis. The investigation unveils the coarsening process, shedding light on the formation of more stable phases and associated compositional changes, including the incorporation of substitutional elements and carbon depletion (resulting in low stoichiometry, x<1) within the newly developed (Ti,M)Cx. Additionally, the increased carbon content contributes to pearlite emergence within the steel matrix. Notably, key factors influencing the distinct morphologies observed in growing TiC particles are identified, attributed to variations in Mo, V, and W concentrations, as elucidated by rigorous thermodynamic and first-principles calculations. This study represents significant progress in understanding the intricate microstructure development of high-volume TiC-steel composites.

Tuning high- and low-temperature rheological properties of warm-mixing asphalt composites by functionalized waxes

Tuning high- and low-temperature rheological properties of warm-mixing asphalt composites by functionalized waxes

Studying the stability of polymer nanoparticles by size exclusion chromatography of radioactive polymers

The properties of nanomedicines will influence how they can deliver drugs to patients reproducibly and effectively. For conventional pharmaceutical products, Chemistry, Manufacturing and Control (CMC) documents require monitoring stability and storage conditions. For nanomedicines, studying these important considerations is hindered by a lack of appropriate methods. In this paper, we show how combining radiolabelling with size exclusion chromatography, using a method called SERP, can inform on the in vitro degradation of polymers. Using nanoparticles composed of biodegradable poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA), we show that SERP is more sensitive than dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) to detect degradation. We also demonstrate that the properties of the polymer composition and the nature of the aqueous buffer affect polymer degradation. Importantly, we show that minute changes in stability that cannot be detected by DLS and NTA impact the pharmacokinetic of nanoparticles injected in vivo. We believe that SERP might prove a valuable method to document and understand the pharmaceutical quality of polymer nanoparticles.

Design of highly-sinterable LATP-CNT composite powder by sequential particle assembly for fabrication of highly electrical-conductive composite electrodes

A sequential particle assembling process was developed to fabricate composite particles with multiple components. Cobalt sintering aids and carbon nanotube (CNT) conductive additives were sequentially and electrostatically absorbed on Li1.3Al0.3Ti1.7(PO4)3 (LATP) electrolyte particles under various dispersion conditions. The effect of the particle assembling conditions on the composite body's sintering ability and conductive properties was investigated. By optimizing the microstructure of the composite particle and its particle charging conditions, it became possible to obtain a sintered composite electrode with a finely connected path of each LATP and CNT phase

Experimental evaluation of atmospheric plasma treatment effects on different textures of CFRP composite for aircraft applications

This article examines the impact of Atmospheric Plasma Treatment (APL) on the chemical composition and fracture properties of various textured surfaces (tool and bag side) of carbon fiber/epoxy (CFRP) composites utilized in aircraft applications. For this purpose, parameters of atmospheric plasma (APL) surface treatment were evaluated in comparison to chemical cleaning and peel-ply applications, taking into account its effects on surface properties and adhesive bond strength. A comprehensive variety of surface characterization techniques were utilized to analyze surface modifications, including water and diiodomethane contact angle measurements for assessing surface hydrophilicity, Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR) and X-ray Photoelectron Spectroscopy (XPS) for analyzing chemical composition and functional groups, and Profilometry, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) for evaluating surface topography and morphology. Experimental results indicated that the reduction in the contact angle following plasma treatment correlated with the elevated oxygen concentration and the presence of polar functional groups (e.g. -OH, -NH2, -NH3, C=O, O-C=O) on the composite surface. Plasma treatment, especially at low nozzle speeds, increased surface roughness on the bag side surfaces. This prevented adhesive penetration and led to gas entrapment, resulting in adhesive failure mode and reduced single lap shear strength for the bag side. In contrast, on the tool side surfaces, the plasma treatment led to a remarkable 19.7% enhancement in shear strength, highlighting its effectiveness.

Optimization of Composite Enzymatic Extraction, Structural Characterization and Biological Activity of Soluble Dietary Fiber from Akebia trifoliata Peel

In order to reduce the waste of Akebia trifoliata peel and maximize its utilization, in this study, on the basis of a single-factor experiment and the response surface method, the optimum technological conditions for the extraction of soluble dietary fiber from Akebia trifoliata peel with the compound enzyme method were obtained. The chemical composition, physical and chemical properties, structural characterization and biological activity of the purified soluble dietary fiber (AP-SDF) from the Akebia trifoliata peel were analyzed. We discovered that that the optimum yield was 20.87% under the conditions of cellulase addition 600 U/g, enzymolysis time 100 min, solid–liquid ratio 1:24 g/mL and enzymolysis temperature 51 °C. At the same time, AP-SDF was a porous network structure cellulose type I acidic polysaccharose mainly composed of arabinoxylan (36.03%), galacturonic acid (27.40%) and glucose (19.00%), which possessed the structural characteristic peaks of the infrared spectra of polysaccharides and the average molecular weight (Mw) was 95.52 kDa with good uniformity. In addition, the AP-SDF exhibited high oil-holding capacity (15.11 g/g), good water-holding capacity and swelling capacity, a certain antioxidant capacity in vitro, hypoglycemic activity in vitro for α-glucosidase inhibition and hypolipidemic activity in vitro for the binding ability of bile acids and cholesterol. These results will provide a theoretical basis for the development of functional products with antioxidant, hypoglycemic and hypolipidemic effects, which have certain application value in related industries.

Catalytic upgrading of Naomaohu coal pyrolysis volatiles over NiAl and NiLiAl oxides

Catalytic upgrading of volatiles is an essential technology to improve the product distribution of pyrolysis for the clean and efficient utilization of low-rank coals. In this work, novel acid-base bifunctional catalysts composed of Ni/Li/Al oxides were designed and prepared using LDH precursors with tunable chemical composition and structural properties. The catalysts were systematically characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), physisorption, NH3-temperature programmed desorption (NH3-TPD), CO2-temperature programmed desorption (CO2-TPD), H2-temperature programmed reduction (H2-TPR), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). A two-stage fixed bed reactor was employed to evaluate the performance of the catalysts. Characterization results suggest that the crystal size of NiO and the surface area of the catalyst decreased with increasing Li content and decreasing Ni content in the catalyst, while the pore volume and pore diameter were positively correlated with Li content. Moreover, the addition of Li reduced the amount of weak acid sites and raised the amount of total basic sites. Consequently, the bifunctional catalysts boosted the yield of light tar and the contents of aromatics and phenols in tar. Specifically, with the highest total acid sites (569 μmol/g) promoting the cracking of heavy pitch components, Ni2.5Li0.5Al1 decreased the content of pitch in tar to 23.8wt.%, representing a 42.7% drop from the corresponding non-catalytic pyrolysis. Accordingly, it improved the light tar yield to 7.2wt.%, which was 18% higher than non-catalytic pyrolysis. 450°C is identified as a suitable temperature for the catalytic upgrading of volatiles from Naomaohu coal; higher catalysis temperatures at 500°C and 550°C led to lower tar yield and lower phenols content, along with higher gas yield and more carbon deposition.

Facile one step green synthesis of CdO-CdS hybrid nanocomposite: Its electrochemical and photoluminescence applications

This study reports the fabrication of a CdO-CdS hybrid nanocomposite (CDCS NC) and its application towards electrochemical sensing of dopamine (DA). The synthesis was conducted at various temperatures using Butea monosperma leaf powder as a green fuel and it was noticed in the XRD pattern that 400 °C was ideal for the formation of the CdO-CdS hybrid NC. Also, the samples were characterized by implementing Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), UV-Vis Diffused Reflectance Spectroscopy (UV-DRS) and Photoluminescence (PL) techniques. The electrochemical activity was investigated using Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) techniques. A working electrode was fabricated by modifying a Glassy Carbon Electrode (GCE) using the CdO-CdS NC and it showed remarkable electrochemical activity towards dopamine (DA). Further, the electrochemical properties were investigated by varying the scan rate, pH and concentration. The fabricated electrode shows a low limit of detection of 23 µM. Hence by its unique composition and inherent properties, the NC stands as a potent tool for advancing the boundaries of electrochemical sensing, heralding a new era of innovation in sensor development.

Aerosol assisted-chemical vapour deposition of tetrahedrite copper antimony sulphide thin films: the effect of zinc(II) impurities on optical properties

Non-stoichiometric semiconducting copper antimony sulphide (CAS) thin films, both undoped and with Zn2+ ions incorporated, were deposited at 500, 550 and 600°C onto glass substrates by aerosol-assisted chemical vapour deposition (AACVD) using metal diethyldithiocarbamate precursors. Data from powder X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and scanning electron microscopy – energy dispersive X-ray spectroscopy suggest a correlation of composition of the non-stoichiometric sulphur-deficient tetrahedrite phase (cubic structure) microcrystalline CAS (Cu12Sb4S13) thin films with particle sizes ranging from 0.1 to 4 µm. For undoped thin films, visible optical absorption with a bandgap of ∼2.1 eV is likely associated with compositional variations involving intrinsic lattice defects, including shallow electronic states such as copper interstitials and vacancies of sulphur as deep-lying donors, and copper-antimony anti-sites and antimony vacancies as deep-lying acceptors. Additionally, tetrahedrite phase CAS (tCAS) thin films with Zn2+ ions incorporated (Znx-tCAS) exhibit tunable composition-driven electronic structure for small Zn2+ content influencing narrower bandgaps between 1.7 and 1.9 eV. The Raman data suggest that the phase purity is affected by small fractions of the famatinite (tetragonal) phase. Overall, the thin films display broad emission of fast dual radiative recombination, and an additional recombination pathway exhibited for Znx-tCAS associated with zinc-related point defects. Though further studies are required to explore in more detail the defect chemistry, these results show the utility of AACVD in tuning compositional and optical properties of undoped tCAS and Znx-tCAS thin films.

Gluten-free baked products formulated with Jerusalem artichoke (Helianthus tuberosus) flour

Gluten-free baked products (GFBPs) usually present unbalanced nutritional and unappealing organoleptic characteristics (e.g. excessive hardness and pale color) when compared to cereal-based products containing gluten. Jerusalem artichoke tubers store inulin and fructooligosaccharides, compounds with nutritional and functional attributes suitable for the diets of persons with diabetes and obesity. This work proposes to improve the nutritional and organoleptic characteristics of GFBPs formulated from a base gluten-free premix of maize and cassava starch, and rice flour, by partial substitution (0-70%) of both starches with Jerusalem artichoke flour (JAF). JAF proximate composition and technofunctional properties were evaluated, standing out its high water retention capacity (3.30±0.21 g/g), which was 2 and 3 times higher than that of rice flour and corn and cassava starches, respectively. Firstly, a sweep of replacement percentages for cassava and corn starches with JAF was conducted. The GFBPs formulations assayed were: rice flour (30%), cassava starch (0-30%), maize starch (0-40%), and JAF (0-70%). From color and texture results, the formulations containing 20 (T20) and 40% (T40) of substitution were selected and scaled up, and the respective GFBPs were characterized by moisture content, aw, color, weight, volume, alveolar distribution, and crumb and crust texture properties. The luminosity (L*) of the dough and crust decreased significantly (p<0.05) with increasing JAF content (from 88.10±0.96 to 44.31±0.74 and from 81.19±1.59 to 35.25±1.50, respectively). Hardness was significantly reduced (p<0.05) by JAF replacement in T40 compared to the control, from 4.68±1.60 to 1.71±0.34 N for the crumb and from 31.67±9.81 to 3.00±3.31 N for the crust. The T20 samples presented greater alveolar area and circularity of the alveoli, resulting in a GFBP with better textural and organoleptic attributes. Both formulations were acceptable when subjected to a sensory analysis, but consumers showed greater preference for the samples with 40% JAF.

Influence of seasonality and habitat on chemical composition, cytotoxicity and antimicrobial properties of the Libidibia ferrea

Influence of seasonality and habitat on chemical composition, cytotoxicity and antimicrobial properties of the Libidibia ferrea

Machine-Learning-Assisted Descriptors Identification for Indoor Formaldehyde Oxidation Catalysts.

The development of highly efficient catalysts for formaldehyde (HCHO) oxidation is of significant interest for the improvement of indoor air quality. Up to 400 works relating to the catalytic oxidation of HCHO have been published to date; however, their analysis for collective inference through conventional literature search is still a challenging task. A machine learning (ML) framework was presented to predict catalyst performance from experimental descriptors based on an HCHO oxidation catalysts database. MnOx, CeO2, Co3O4, TiO2, FeOx, ZrO2, Al2O3, SiO2, and carbon-based catalysts with different promoters were compiled from the literature. Notably, 20 descriptors including reaction catalyst composition, reaction conditions, and catalyst physical properties were collected for data mining (2263 data points). Furthermore, the eXtreme Gradient Boosting algorithm was employed, which successfully predicted the conversion efficiency of HCHO with an R-square value of 0.81. Shapley additive analysis suggested Pt/MnO2 and Ag/Ce-Co3O4 exhibited excellent catalytic performance of HCHO oxidation based on the analysis of the entire database. Validated by experimental tests and theoretical simulations, the key descriptor identified by ML, i.e., the first promoter, was further described as metal-support interactions. This study highlights ML as a useful tool for database establishment and the catalyst rational design strategy based on the importance of analysis between experimental descriptors and the performance of complex catalytic systems.

In situ and ex situ investigation on the product films evolution of pipeline steel under AC interference and high cathodic protection conditions

An in situ Raman measurement set-up coupled with AC interference and CP circuits was developed to provide more intuitive detection data for combined action AC and CP corrosion processes. Combined with XPS, AFM and other ex situ surface analyses and electrochemical tests, the evolution of composition, structure and electrochemical properties of surface film is studied. Initially, a passive film is formed on specimen surface, which undergoes successive redox processes. Eventually, the passive film evolves into magnetite and rust, and hydrogen evolution produces mechanical damage to rust layer. Based on this, the model for the evolution of AC corrosion is constructed.

Effects of Electron Beam Radiation on the Phenolic Composition and Bioactive Properties of Olive Pomace Extracts

Olive pomace is an agro-industrial waste product generated from the olive oil industry and constituted by bioactive compounds with potential applications in several industrial sectors. The purpose of this work was to evaluate the effects of electron beam (e-beam) radiation on olive pomace, specifically on phenolic compounds (by HPLC–DAD–ESI/MS) and the bioactive properties (antioxidant, antiproliferative, and antimicrobial activities) of crude olive pomace (COP) and extracted olive pomace (EOP) extracts. The amount of total flavonoid content and the reducing power of COP extracts were higher than those obtained for EOP extracts. The results suggested that e-beam radiation at 6 kGy increased both total phenolic and total flavonoid contents as well as the reducing power of COP extracts, due to the higher extractability (&gt;2.5-fold) of phenolic compounds from these samples, while decreasing the scavenging activity of extracts. The extracts of both olive pomaces showed antibacterial potential, and COP extracts at 400 µg/mL also presented antiproliferative activity against A549, Caco-2, 293T, and RAW264.7 cell lines, with both properties preserved with the e-beam treatment. All in all, e-beam radiation at 6 kGy appears to be a promising technology to valorize the pollutant wastes of the olive oil industry through enhancing phenolic extractability and bioactive properties, and, furthermore, to contribute to the environmental and economical sustainability of the olive oil industry.

Magnetic Three-Dimensional Graphene: A Superior Adsorbent for Selective and Sensitive Determination of Nitrite in Water Samples by Ion-Pair Based-Surfactant-Assisted Solid-Phase Extraction Combined with Spectrophotometry

A straightforward, fast and efficient analytical method was developed which utilizes a magnetic composite called three-dimensional graphene (3D-G@Fe3O4) as an adsorbent to recover nitrite ions (NO2−) from environmental water samples. The investigation into the synthesized adsorbent contained an examination of its morphology, chemical composition, structural attributes, and magnetic properties. This comprehensive analysis was conducted using various instrumental techniques, including Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), and vibrating sample magnetometry (VSM). The adsorbent surface was activated by adding cetyltrimethylammonium bromide (CTAB) to the sample solution. To improve the selectivity and sensitivity of the method, nitrite ions were reacted with sulfanilic acid and chromotropic acid sequentially. An orange-red azo-dye complex was formed in the presence of nitrite ions with a clear absorbance peak at 514 nm. The effect of the main experimental parameters such as the pH of the sample solution, adsorbent dosage, and CTAB dosage was explored, and the optimization process was performed using a central composite design (CCD). The linear dynamic range (20–100 ng mL−1) was determined under optimal experimental circumstances, yielding a reasonable determination coefficient (R2, 0.9993), a detection limit of 5.12 ng mL−1, an enrichment factor of 167, and precision values of 1.0% intraday and 2.9% inter-day. The methodology successfully identified minute nitrite ions in environmental water samples with relative recoveries that varied between 96.05 and 101.6 ng mL−1.

Multiferroic properties of composites made up of ferromagnetic Co0.9Ni0.1Fe2O4 and La0.67Sr0.33MnO3 with ferroelectric 0.5Ba0.7Ca0.3TiO3-0.5BaZr0.2Ti0.8O3

Multiferroic properties of composites made up of ferromagnetic Co0.9Ni0.1Fe2O4 and La0.67Sr0.33MnO3 with ferroelectric 0.5Ba0.7Ca0.3TiO3-0.5BaZr0.2Ti0.8O3

Multi-response optimization of reinforcement parameters of aluminum alloy composites by Taguchi method and grey relational analysis

The present work describes the optimization of reinforcement parameters for hardness, thermal conductivity, and coefficient of thermal expansion while developing LM6 alloy/soda-lime glass particulate composite through Taguchi-based Grey Relational Analysis (GRA). Soda-lime glass particle weight % (1.5, 3.0 and 4.5%), particle size (100, 150 and 300 microns) and pre-heat temperature (260, 380 and 500oC) are varied accordingly to explore the effect of reinforcement parameters on LM6 alloy/soda-lime glass composite properties. Composites are developed through stir casting based on the L9 Taguchi orthogonal array approach. The properties such as hardness, thermal conductivity and coefficient of thermal expansion of developed composites are assessed. Signal to Noise Ratios (S/N ratios) are calculated and used for the optimization of parameters. GRA is employed for multi-response optimization to find the levels of parameters that affect the desirable properties of the composite. Thus, the reinforcement parameters are optimized for attaining the combined objectives of higher hardness, higher thermal conductivity and lower coefficient of thermal expansion values considered in this investigation. The analysis shows that 4.5 wt. %, particle size of 200 microns and pre-heat temperature of 380oC are optimal parameter levels. A confirmation test is carried out with the optimal parameter levels and the GRG value of 0.7778 is obtained. The GRG with the initial parameter settings is 0.4711, and the improvement of GRG is found to be 65.1%. ANOVA is performed on GRG to find out significant parameters and the contribution of each parameter is identified. The wt.% of soda-lime glass is the most significant parameter and its contribution is 92.6%.

Plastic deformation and fracture mechanisms of a novel Al/Mg bimetal composite at cryogenic temperatures

Examining the cryogenic-temperature characteristics of composites is imperative for ensuring the sustained functionality of their components in environments with cryogenic temperatures. The plastic deformation and fracture mechanisms of a novel Al/Mg bimetal composite (5052/AZ31B alloys bimetal composite) fabricated by the corrugated and flat rolling were investigated at cryogenic temperatures in this study. A mixture-law constitutive model was established to describe the flow behaviour of each constitute alloy of bimetal composite based on the stress-strain relationships obtained from cryogenic tensile tests, which were performed on a universal testing machine equipped with a liquid nitrogen in the temperatures of -180 °C, -80 °C and room temperature (RT) at the strain rate of 0.001 s-1. It is found that the elastic modulus of the 5052/AZ31B bimetal composite experiences minimal impact at lower temperatures, whereas the flow stress shows an increase with decreasing temperature. The AZ31B layer exhibits a quasi-disintegrated brittle fracture and reduced elongation to failure, leading to premature fracture, while the 5052 layer demonstrates a mixed tough-brittle fracture and increased plasticity, resulting in a two-stage fracture process with AZ31B fracturing earlier at the temperature of -180 °C. These findings align with finite element simulations, validating the intricate interplay between bimetal composite properties and cryogenic temperature in influencing fracture behaviour.